Would someone explain the change to the gem cast when damage taken. Also I want to know what is a fair price for Geofri's Baptism? I saw one in regular chat and I was busy fighting monsters so I did not get a chance to trade for it.

They have made it that the gem level requirements of the supported gems cannot exceed the requirements of the CoDT gem.

I have one of those maces , I'll do some research and find out what a good price us and do you a good deal if you want ?

I always think about this when making a character and go with it because I assume someone did the math, but in cruel difficulty Kraityn offers 8% increased attack speed. I'm assuming this isn't as good as 12% physical from Oak?

From my point of view, CwDT works just the same as before:Keep it lvl1 and link Enduring Cry and Molten Shell on it.

You can still use the gem to trigger "hi-power" (= hi-lvl gems) stuff frequently (whenever a small amount of damage taken ie often). We do that to keep up our Endurance Charges and/or Molten Shell.
Patch changed the way a high-lvl CwDT gem works, so it only cast weak (low-lvl) linked gems.

PS.
I am now trying out Temporal Chains as the 4th gem in my CwDT 4L. Not bad, but i should chrom my gear and use Enfeeble instead: much better for high-lvl maps, but it needs a fare amount of Int (151 for lvl20)...

I have Decoy totem as my 4th link. It helps me with survivability a lot if you need that sorta thing in Merciless. I still have terrible gear and I'm underleveled because this build is so OP. I am getting gaped now in Merciless Act 3 but I think it's because of gear, resists, and it's supposed to be hard. I will say the totem gets 1 shotted by bosses in Merciless so it doesn't buy you much time, but sometimes all you need is aggro off you for a second. Just a thought.

I'm also a bit confused as to where you get some of your numbers. I'm level 62 with just over 3k health and my health regen per second is just over 100. Build says 200 expected. Is this from + life gear? I still have a few health nodes to hit but I doubt it's going to double my regen per second.